The present invention relates to body building exercise apparatus and in particular to exercise apparatus of the portable type. Various forms of exercise apparatus are known; the portable type usually provides for pulling and pressing exercises in which work is done in extending or compressing a spring. Also known are devices in which an elongate element is unwound from a spool in performing the exercise, the resistance to movement being applied by a system of springs or by the inertia of a flywheel associated with the spool.
The prior art devices have one problem in common, however, that is that they do not allow long stretching movements. The tension applied in pulling exercise apparatus is mostly determined by the extension of springs where the tension increases towards the end of the movement. Although portable apparatus is known, this has the added disadvantage of being housed in a cumbersome and heavy casing. Adjustment of the power of resistance of such apparatus has up until now been both unsatisfactory and inaccurate. Moreover, in apparatus of the type having an elongate drawing element on a spool, wear on the drawing elements has until now been unavoidable. The most common cause of wear on the drawing element is friction, which creates heat which in many cases cannot be properly conducted away. Another cause of eventual failure of the drawing elements on the inertia reel type of apparatus is the rapid reversal from winding off action to winding on action, and the jerk which occurs when it is fully wound on if the energy in the inertia reel has not all been dissipated before then.